Wheat Gluten and Binders

Wheat gluten is the cohesive protein fraction of wheat, recovered by washing starch from dough, and is marketed as vital wheat gluten at roughly 75-85% protein with exceptional adhesive and elastic properties. In aquafeed it plays a dual role: a highly digestible protein source (protein digestibility often above 90%) for species from salmonids to shrimp, and the workhorse natural binder that gives extruded and steam-pelleted feeds their water stability, typically dosed at 2-6% for binding and up to 10-15% as protein. Good pellets should retain integrity for several hours in water, and gluten, along with guar gum, potato starch, and certain hemicelluloses, is the standard agent. Its amino acid profile is low in lysine, so it is balanced with lysine-rich ingredients. Being largely free of anti-nutritional factors, it is one of the safest plant concentrates for high-inclusion use, though it contains gluten allergens that matter for feed-mill handling rather than fish. Quality metrics are protein content, water absorption index, ash, and microbiological status. In formulation software gluten appears both in the protein line and the binder line, which is why it is priced at a premium over ordinary wheat flour despite similar origin.